Underwater!

Underwater is a 1955 adventure film directed by John Sturges and starring Jane Russell and Richard Egan.

Partially filmed on location in Mexico and Hawaii, Underwater was completed in a newly constructed underwater tank in an RKO Radio soundstage. It was the first RKO film released in Superscope.Lori Nelson claimed Howard Hughes wanted her for the lead and paid Universal Pictures for her use, however Jane Russell owed RKO a film. The lead was given to Russell with a part written for Nelson so she could keep her fee. ........

Source: Wikipedia